This invention relates to an information recording and reproducing apparatus which receives a data stream including content data of programs and additional information including time information with respect to each program in the content data which is currently being transmitted, records it in a recording medium, and reproduces the recorded content, and a method of recording information to a recording medium.
In recent years, digital broadcasting by use of a communication satellite, etc. has become popular. In digital broadcasting, high quality signal transmission is possible, and in addition, multi-channel is realized by improvement of frequency utilization efficiency, and various content such as movies, sports, news, and music are multiplexed to go on the air.
As one example of such content, an all music radio program using digital audio data may be broadcast. For example, there may be a broadcast channel in which music audio data, which was compressed by use of an audio compression system such as MPEG (Moving Picture Experts Group), is broadcast continuously. In addition, a service may be rendered in which data, including various additional information pertaining to the music being distributed, is distributed in parallel with the audio data, and thereby a user, who is listening to music, can visually recognize additional information as to the music, and can also record it in a recording medium together with the audio data of the music. The additional information may include, for example, the name of the music and the name of the artist, such as the musical performer.
On one hand, in recent years, high capacity recording apparatuses which use writable types of DVDs (Digital Versatile Disk) and HDDs (Hard Disk Drive), etc. have been marketed at low prices, and it has become possible to record in such recording apparatuses a number of songs which were distributed in the all music radio program as described above. For example, in the case of distributed music which was compressed and encoded by an MPEG-AUDIO-Layer 2 system, it has become possible to record approximately 700 hours of audio data to HDD with 80 Gbytes of storage.
In the case of recording distributed music in a recording apparatus, the recording is normally carried out by a music unit, and therefore, in the recording apparatus, it is desired to determine a boundary of music which is distributed continuously, and to automatically record audio signals received with respect to each piece of music. In the past, automatic recording of each piece of music was easily realized by automatically detecting a silent period between pieces of music on the basis of the level of audio data which was input. Further, there was also a data transfer system in which, in a receiving apparatus which receives broadcast content in music distribution, etc., the start point of a piece of music is determined from additional information which was transmitted in parallel with the audio data as described above, and an audio signal, which is output from a receiving apparatus to a recording apparatus, is made to be silent for a predetermined time period prior to the start point. Such system thereby enabled the boundary of the piece of music to be accurately determined in the recording apparatus. See, for example, Japanese Patent Publication No. JP-A-2000-36184, described below.
In addition, since it is possible to record the audio data of a number of pieces of music in a high capacity recording apparatus, a technique for easily searching the recorded audio data has been sought. As an example of this, there was a recording apparatus which was configured in such a manner that, when audio data was recorded to a portable optical disk medium such as a DVD, in audio frame information in an audio packet in which a head of the audio frame is included, a fast access unit pointer, which shows a recording position of that head, has been recorded, and at the time of reproduction, it is possible to easily search the start position of the audio frame by use of the fast access unit pointer as a clue See, for example, Japanese Patent Publication No. JP-A-9-251762 (U.S. Pat. No. 5,805,537), described below.
As described above, it is desired to record audio data of an arbitrary piece of music in a recording apparatus in real time at the same time as receiving an all music broadcast channel to listen to and view music, and further to easily search and reproduce audio data which was recorded in the recording apparatus in a music unit. However, during the recording of audio data, when a silent period is to be detected on the basis of the level of audio data which is input in order to determine a boundary of a piece of music, it may not be possible to surely detect the boundary when the silent period between pieces of distributed music is short, and inversely, when the silent period is lengthened and distributed, the number of pieces of music which can be distributed becomes small.
In this regard, it is desired to describe the performance time of a piece of music and the elapsed time, etc. in additional information which is distributed in parallel with the audio data, and to surely detect the starting point of the piece of music by the use of this information. However, in order to realize such automatic detection in a conventional system, processes such as the exchange of signals between a receiving apparatus which receives broadcasts and a recording apparatus, and the generation of information to be recorded, become complex. In particular, in recent years, apparatuses for recording video/audio data in an HDD have increased, and it is desirable to record audio and video data received through broadcasting in an HDD in real time with simple processing, and to easily search data which was recorded.
Meanwhile, in the recording apparatus which was disclosed in Japanese Patent Publication No. JP-A-9-251762, after an audio signal is input, that audio signal and control information are stored in an HDD, and thereafter, information which was read out from the HDD is multiplexed and recorded on a recording medium, and it is difficult to receive the input of an audio signal and record information which shows a head part of that audio signal and music, etc. in real time.